Polymer compositions that include polydiacetylene segments are used for a variety of applications. Diacetylenes are typically colorless and undergo addition polymerization, either thermally or by actinic radiation. As the polymerization proceeds, these compounds undergo a contrasting color change, typically from colorless to blue or purple. Furthermore, when exposed to external stimuli such as heat, physical stress or a change of solvents or counterions, polydiacetylenes exhibit further color changes produced by distortion of the planar backbone conformation. Polydiacetylene assemblies are known to change color from blue to red with an increase in temperature or changes in pH due to conformational changes in the conjugated backbone as described in Mino, et al., Langmuir, Vol. 8, p. 594, 1992; Chance, et al., Journal of Chemistry and Physics, Vol. 71, 206, 1979; Shibutag, Thin Solid Films, Vol. 179, p. 433, 1989; Kaneko, et al., Thin Solid Films, Vol. 210, 548, 1992; and U.S. Pat. No. 5,672,465. Utilization of this class of compounds is known for use as biochromic indicators as discussed in U.S. Pat. No. 5,622,872 and publication WO 02/00920.
In addition to the polymerization of monomeric diacetylenes, it has been demonstrated that the diacetylene functionality can be incorporated in the repeat structure of a polymer backbone. These types of polymers undergo solid-state cross-polymerization on exposure to U.V. radiation, and form, polydiacetylene chains. These materials have been referred to as macromonomers due to the systematic polymerization of the diacetylene units within the backbone structure of the initial polymer. Examples of polymers containing the reactive diacetylene functionality in the repeat structure of the polymer backbone formed by linking the appropriate difunctional monomers together, wherein one of the difunctional monomers contains the diacetylene group, include the diacetylene-urethane copolymers described in U.S. Pat. Nos. 4,215,208 and 4,242,440; segmented copolymers formed from diisocyanate reacted with elastomeric prepolymer and chain extended with a diacetylene described in U.S. Pat. No. 4,721,769; linear block copolymers with a soft segment (polyether, polyester, polydiene, polydimethylsiloxane) and a diacetylene-containing hard segment (polyurethane, polyamide, polyester, polyurea) as described in U.S. Pat. No. 4,767,826; and polyamide-diacetylene copolymers as described in U.S. Pat. Nos. 4,849,500 and 4,916,211.